Variable pitch propeller



F F. KUCERA ET AL 1,346,600

VARIABLE PITCH PROPELLER Filed Dec. 17. 1930 O E: P QD KUcERB Q PH PETE? G OOPENHHUF ATTORNEY Pa ented Feb. 23, 1932 UNITED STATES PATENT OFFICE vazemnm rrrcn: rnormnn Application filed December 17, 1930. Serial No. 502,902.

This invention relates to new and useful improvements in avariable pitch propeller.

The invention has for an object the provision of a variable pitch propeller which is characterized by propeller blades rotatively mounted in a casing having a bore for receiving a propeller shaft, a lock collar slidably mounted coaxially to said bore and connected to lock the propeller blades in various adjusted positions, and a second control collar slidably mounted coaxially with said bore and connected for changing the angles of the blades when the latter elements are in an unlatched condition. It isa further object of this invention to provide propeller blades which may be set and locked in various degrees to either side of the neutral line so as to form a right hand or left hand propeller. This allows the propeller to be used as a traction or to prevent raking effects.

'While an aeroplane is in flight,the propeller may be used to propel the plane, and during landing the blades may be adjusted so as to act as brakes and speed down the plane in its landing. It is generally known that it is highly desirable to decrease the speed of a plane during landing. The propeller could be used with equal advantageous results in the marine or other arts.

It is a still further object of this invention to provide a tubular member on the casing from which the'propeller blades project and in which there is a bore, and to arrange the collars which control the latched condition of the propeller blades and the adjusting of the propeller blades to be slidable on said tubular member. v

As a still further object of this invention it is proposed to provide means for normally urging the locking collar into a position in which the propeller blades are latched and to groove the collar for the receiving of a fork for connection with the levers to control its operation from the cockpit of the plane or similar portion of another device.

It is a still further object of this invention to provide a means for turning the blades of the propeller simultaneously in opposite directions controlled by said control collar and to groove the collar for receiving a fork for connection with control mechanism to set the blades as desired.

A still further object of this invention is to construct a device of the class mentioned which is of simple durable construction, dependable in use and efficient in action, and which can be manufactured and sold at a reasonable cost.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more 6 particularly set forth.

. In the accom anying drawings forming a material part 0 this disclosure Fig. 1 is an elevational view of a variable pitch propeller constructed according to this invention, shown with a portion of the casinggremoved to disclose interior parts.

ig. 2 is a sectional view taken on the line 2-2 of Fig. 1, and r Fig. 3 is a transverse sectional view taken on the line 3-3 of Fig. 2.

The device-has a hollow casing 10 with a. tubular central projection 11 having a bore 12 extending through said casing and projection for engagement upon a propeller shaft. The casing 10 is made from two sections, indicated by reference numerals 12 and13 re .s ectively, and normally bolted together. In

ig. 1 apertures 14 are illustrated for the passage of bolts to connect the parts. The central portion 15 of the casing 10 is of box shape as may be understood by considering Figs. 1 and 3. On opposite sides of the cen--' tral portion a pair of tubular ends 16 project. The tubular projection 11 extends inwards through the box portion of the casing and is indicated within the casing by reference numeral 17. i

The tubular portion 17 within the casing is also split so that a portion thereof is upon the casing section while the remaining portion upon the casing 13, and when these sections are together the parts are in line as shown in Fig. 2. The bore 12 extends comms pletely from one end through to the other end tions.

of the casing. A plurality of flutes 18 are formed within the bore for engaging in corresponding grooves upon a propeller shaft. The ends of the bore 12 are chamfered, indicated by reference numeral 19, for ease in inserting the device upon a shaft.

Diametrically opposite, propeller blades' 20 project from and have shanks 21 rotative- 1y mounted in said casing 10 so that their axes are at right angles to the axis of the bore 12. The shanks 21 engage in the tubular ends 16 of the casing and are formed at their inner ends with flanges 22. Cylindrical bearings 23 are used for rotatively supporting the shanks and thrust bearings 24 are arranged beneath the flanges 22 so as to prevent the propeller blades from flying outwards under centrifugal forces. A lock ring'25 with teeth 26 is attached upon each of the shanks 21. These lock rings are disposed within circular recesses 27 formed within the tubular end 16 of the casing.

A lock collar 28 for connection with control means is provided with lock fingers 29 engageable with the teeth 26 and is slidably mounteduponthetubularprojection12. The lock collar 28 is formed with a peripheral groove 30 for receiving a fork, not shown on the drawings but schematically indicated by dot and dash lines 31, for connection witi suitable linkage to extend to the control pit of the device provided with the propeller. The lock fingers 29 are on diametrically opposite sides of the lock collar 28 and extend into the tubular end 16 of the casing so as to be capable of engaging the teeth 26.

A means is provided for normally urging the lock fingers 29 into their engaged posi- This means comprises studs 82 projecting from the casing 10 and holding at their outer ends caps 33. Coaxial springs 34. are arranged upon the studs and act between the caps 33 and the inner ends of cups 35 fixedly mounted in apertures formed in connecting portions which integrally connect the fingers 29 with the lock collar 28. The cups 35 have outturned flanges 36 which are disposed upon the outer sides of the portions mentioned and inturncd inner flanges 37 against which the inner ends of the springs 36 act. The normal action is that the springs 34 urge the lock fingers 29 and the collar 28 into the operative position.

A pitch control collar 38 for connection with control means, in the vicinity of the pilot or operator of the device, is slidably mounted upon the tubular projection 11 and is connected with means for varying the an gular positions of the blades 20. The lock collar 38 is formed with a peripheral groove 39 for receiving a fork from a control lever. Dot and dash lines 40 schematically indicate this tornn-since it forms no part of this invention. Preferably. the fork should be connected up to move through very small distances and this is possible by the revision of an electric motor, schematically indicated by reference numeral 41, which is provided with a work gear 42 meshing with a worm wheel 43 on a crank shaft 44 to which the control fork 40 is connected.

As before stated, a means is provided for transmitting movements from the control collar 38 to turn the propeller blades 20 simultaneously in opposite directions, either in one or in the other way. This means is in the form of a pair of tubes 45 fixed upon the collar 38 and extending from the collar 28 and into the casing 10. At the inner ends the tubes 45 connect with a slide 16 which is slidably mounted upon the tubular member .17. This slide is formed with opposite ends 47 arranged to be slidably gu ded by the sides of the box portion 15 of the casing. These opposite ends 47 are formed with transverse slots 48 which in turn receive pegs 49 eccentrically mounted upon the flanges 22.

The operation of the device may be traced by assuming it in a position as shown on the drawings. In the event that it is desirable to change the pitch of the propeller, the control means 31 is first operated to move the collar 28 so that the catch fingers 29 disengage from the teeth 26. Next the control mechanism for moving the lever indicated at 4:0 is operated to move the control collar 38 and cause the slide 46 to move and correspondingly cause the pivoting of the blades 20 on their shanks 21. After a new position has been reached, the lock fingers 29 are released and the springs 34 automatically return them into the locking positions.

While we have illustrated and described our invention with some degree of particularity, we realize that in practice various alterations therein may be made. We therefore reserve the right and privilege of changing the form of the details of construction or otherwise altering the arrangement of the correlated parts without departing from the spirit or the scope of the appended claims.

Having thus described our invention, what we claim as new, and desire to secure by United States Letters Patent is 1. In a variable pitch propeller, a hollow casing with a tubular central projection and a bore extending through said casing and projection for engagement upon a propeller shaft, diametrically opposite propeller blades projecting from and having shanks rotatively mounted in said casing so that their axes are at right angles to the axis of said bore, a lock ring with teeth fixed on each of said shanks, and a lock collar for connection with control means and having lock fingers engageable with said teeth and being slidably mounted on said tubular projection.

2. In a variable pitch propeller, a hollow casing with a tubular central projection and a bore extending through said casing and casin 3. %n a variablefpitch propeller, a hollow casing with a tubular central projection and a. bore extending through said casing and projection for engagement upon a propeller shaft, diametrically opposite propeller blades caps and against the inner en ing and'carrying caps, expansion springs coaxially on said studs and acting-against said of on s at tachedupon su ports connecting sai lock fin ers with sai lock collar.

igned at Table Rock, in the county of Pawnee and Stateof Nebn, this 4th day projecting from and having shanks rotative- 1y mounted in said casing so that their axes are at right angles to the axis of said bore, a

lock ring with teeth fixed on each of said.

shanks; a lock collar for connection with con December, A. D 1930. FRED KUOERA. RALPH PETER GOODENHAUF.

trol means and having lock fingers on age- I able with said teeth and being sli abl mounted on said tubular projection, said loc fingers projecting from saidlock collar and engaging through openings in said casing and against the teeth on said lock rings.

4. In a variable pitch pro eller, a hollow casing with a tubular centra projection and a bore extending through said casing and pro jection .for engagement upon a propeller shaft, diametrically opposite propeller blades projecting from and having shanks rotative- 1y mounted in said casing so that their'axes are at right angles to the axis of said bore, a

lock ring with teeth fixed on each of said shanks, a lock collar for connection with control means and having lock fingers en a able with said teeth and being sli a l a mounted on said tubular projection, said 100 fingers projecting from said lock collar and engaging through openings in said casing and against the teeth on said lock rings, and means being provided forurging the lock fingers into operative positions.

5. In a variable pitch propeller, ahollow casing with a tubular central projection and a bore extending through said casing and projection for engagement upon a propeller shaft, diametrically opposite propeller blades projecting fromand having shanks rotative- 1y mounted in said casing so that their axes are at right angles to the axis of said bore, a lock ring with teeth fixed on each of said shanks, a lock collar for connection with control means and having lock fingers en ageable with said teeth and being sli abl mounted on said tubular projection, said 100 fingers projectingfrom said lock collar and engagin through openings in said casing and against tlie teeth on said lock rings, and means being provided for urging the lock fingers into operative ositions, said latter means comprising stuns projecting from said casat H 

